Enterprise network is a private network or a virtual private network established inside an enterprise and providing services for the business activities of the enterprise.
Currently the enterprise network popularly used is a communication system based on unified Centrex service, wherein the system is based on a Service Delivery Platform (SDP) service model of telecommunication operator IP Multimedia Subsystem (IMS) network. The unified Centrex service is a realization of such kind of service on the IMS, covers all business operations, supports multiple user access methods, and provides converged services to the users of the IMS and CS-domain mobile phones.
However, the unified Centrex service based on the IMS/SDP service model mainly focuses on operator network, and thus has very distinctive operational and controlling characteristics; the system is highly complicated and has high costs of deployment and usage. Meanwhile, the IMS/SDP architecture doesn't provide sufficient support for the IT system widely used in enterprises, and thus is difficult to meet the requirements of enterprise users.
Therefore, it is in urgent need to provide a communication system which could overcome the problems of existing communication systems such as high complexity and high costs of deployment and usage.